Yup I get what you mean. One of my favorite examples of the difference is Divergence Eve. While completely chock full of fanservice, it's all incidental, and the plot/dialogue itself has no "ecchi" to it. Which is what reviewers say is it's main fault. It's trying to do two things at once: be a super-bouncy colorful show about a team of babes in sexy military outfits (visually) while also trying to be a gritty noir sci-fi horror with political intrigue and existentialism (plot and dialogue). While both parts are executed well, each part gets in the way of most people who would like to watch a show for one or the other.
Another show with this sort of discordance was Madan no Ou to Vanadis. Basically about 2/3rds of the time the show is a medieval mildrama, similar to Arslan no Senki, but then the top generals of one country (literally just one of the nations) are all giant-boobed valkyrie/magical girls. Naturally, the hero is expelled from his own country and becomes a vassal of one of the big-boob generals, and the other big-boob generals are fighting for his attention. But most of the time it is in fact a mildrama with battle formations, tactics, politics and intrique (and people who wear normal clothing). So you have the odd juxtaposition of these two types of show, game-of-thrones type shit and harem-antics type shit. And sometimes the seams really show more than others. One episodes was almost 100% battles and complex tactics and negotiating between regular generals, but then they felt the need to insert a "accidentally sees the magical babes in the hot spring / random boob grope" scene right at the end. It had the feeling of a design-by-committee anime, where someone was checking whether each episode had it's "boobie quota" and that episode with the battles didn't, so they inserted a completely unnecessary hot springs scene at the end, using the girl characters who didn't even appear in the frikking episode itself.